This invention relates to video systems and, more particularly, to a method and means for deriving from video signals, a set of second signals indicative of the characteristics of dynamic changes taking place in a second area and determining change, speed and direction.
The improvement disclosed herein, lies in the selectors and counters which sum certain characteristics of change found in two to four video frames. The prior art methodology of determining change within two video frames is with the combination of camera, delay, comparator and timing generator. This invention discloses additional novel functions to the combination. A dimension selector is added. The selector selects and sorts vertical change from horizontal change and the associated accumulators sum the vertical change as distinct from the horizontal change. additionally, a horizontal direction selector is disclosed, the later selector determines the direction and magnitude of the change, the connected counters sum leftward movement as distinct from rightward movement. At the proper time, these sums are `dumped` into a computer.
No prior art reveals a height/width determiner, derived from a moving subject. Prior art speed and direction determiners derive speed and direction through a differing process. In the prior art system, a wave comparator compares the centerline scan of one period of time with successive "skewed" lines of a different scan to find one line that matches the amount of "skew" of the matching line, thereby determining the direction and speed of the change or moving object.